Fuse



' June 16, 1925. v

' ,c. H. PEARSON FUSE primal Filed m. 7, 1921 2 Sheets-Sheet '1 w) a aJuine '16, 1925.

. c. H. PEARSON FUSE Original Filed Jan, 7, 1921 2 Sheets-Sheet 2' 'moreparticularly to mechanical time fuses- Refile of abandoned applicationSerial Patented June f I f CHARLES. i1. rmnson, or BROOKLINE,MASSACHUSETTS. I

FUSE.

To all whom it may concern:

Be it known that I, CHARLES H. PEARSON,

a citizen of the United States, and resident of Brookline, in thecountyof Norfolk and State of Massachusetts, have invented an Improvement inFuses, of which the followmg description, in connection with the accompanying drawings, is a specification, like reference characters onthe drawings representing like parts;

My present invention relates to fuses, and

adapted to be applied to ordnance shells for the purpose of detonatihgthe charge therein after a predetermined .length of time followiiig thedischarge of the shell from gun In fuses in whielr'the firing pin isarranged to move. at approximatelyright angles to the axis of the fuse,no satisfactory arrangement forpreventing premature detonation of theprimer and chargeof the shell has been devised to the presenttime;

noted above and with the primary object of improving-and perfectingdevices of this character, Ihave devised the subject matter of mypresenti'nvention, in which safety devices are associated with thefiring pin to prevent exploding the primer and the consequent detonationofthe powder charge in the base of: the'fuse. by any action of thefiring pin prior to its being released following the shock of-firing;when such firing pin is installediapproximately at right an gles to theaxis 'of'the fuse.

.In carrying outthis object, I; provide a swivel protecting elementinterposed .be-

tween: the striking point 'of the fi'ri'ngpin' and the primer, saidprotecting element be=- ing held in thisposition of safety by a pin tobe dropped'out of such holding position on the shock of firing and saidelement then moved and being held out of its protecting position by thecentrifugalforce which immediately or quickly follows the shock offiring, leaving the path of the firing pin clear for said firing pin tohit andexploole.

the primer'when the operation of the time train, set at a predeterminedtime,releases the. pin which is then, by the spiralspring surroundingit, snapped .onto and explodes the primer. p Other objects and novelfeatures of con- 'struction and arrangement of parts will ap- No.435,737, filed January 7, 1921.

1924. Serial No. 726,482.

pear as the description of the invention progresses. 3

In the accompanying drawings, illustrating the preferred embodiment ofmy invention,

This application fl led July 17,

Fig. 1 is an elevation of the complete fuse;

Fig. 2 is a central sectional view through i the fuse base, illustratingone-modification I of my improved invention;

6+6 of Fig. "5, looking in thedirection of i the arrows, showing thefiring pin in nor- With a View of obviating the objectionsmal, oroperative position, with "the. rotat able safety device carrying theprimer, interposed in the path of the firing pin and.

.ticularly to Figs. "1, 2, 3 and 4, 10 designates a fuse base providedwith threads 11, bymeans of which it. may be attachedto-the. nose of ashell, and with suitable 'means for holding and allowing theoperation-20f a.

setting'cap 13' for predetermining-the moment of detonation of thecharge within the shell. Arranged diametrically. ofthe fuse:

base and approximately atright angles to the longitudinal axis thereofisa hole;1 t,'- V the outer end of which is adapted tor'eceive the primerholder 15, while the inner end 16 is reduced in diameter to receivethe'shank portion 17 of a firing pin 18, the shankbeing a free slidingfit in said reduced inner end 16. The forward portion 19of the firingpin is a free sliding fit in the hole 14, and' the end of the firingpinis pointed, as shown. A coil spring 20 located in the hole Ji l-behindthe forward portion 19 of the firing pin; surrounds the shank portion 17and nor mally tends to force the firing pin into its operated position,or position in engagement with the primer 21 in the primer holder 15.

Adjacent the rearend of the shank portion 17 is a-circumfere'ntialgroove 22, which,

when the firing pin is forced tothe rear and into its normal position,lies in the circumference of a hole 23, parallel to the axis of the fusebase. Slidably mounted in the hole 23 is a release pin 24, controlled inits movement by the timing train (not shown) normally mounted on the topof the fuse base 10.

Intersecting the hole 14 at a point between the pointed end of thefiring pin in its normal position, and the primer '21 is'a fiat-arcuateshaped chamber 25' in which is pivotally mounted a safety device or arm26, this arm being held in its normal or safety position as shown inFig. 3, by a pin 27 this pin being a rather tight fit in the hole 28,and capable of being moved out of position with respect to the arm 26 bythe shock of firing. An opening 29 through the top of the fuse base 10into the chamber 25 provides means whereby the arm 26 may be assembledin position in said chamher. This pin 27 is a safety device supplementalto the arm 26, and prevents accidental displacement of said arm 26.

\Vith the elements constituting this modification of my improved devicecorrectly assembled in position as shownin the figures referred to, thefiring pin 18 is forced rearwardly in the hole 14, compressing thespring 20, and when the groove 22 comes.

into alinement with the hole 23, the release pin 24 drops into place tohold the firing pin 18 in the operative position just described. The arm26 is now moved into the safety position shown in Fig. 3, by properlymanipulating the fuse base 10, or by means of a suitable instrumentinserted through the hole 29 and the supplemental safety pin 27 insertedin the hole 28. The primer holder 15, with a primer 21 in positiontherein, is positioned in the open end of the hole 14, and the device isset ready for action. Assuming that the timing train '(not shown) is setto operate the release pm 24 at a predetermined length of time after thedischarge of the shell and attached fuse from a gun, and'that the fuse,assembled and set as shown in Fig. 3 is fired from a gun, the shock offiring causes the pin 27 to be driven into the hole 28 and out of thepath of movement of the arm 26. W'hen the shell to which the fuse isattached takes the rifiing of the gun, it is rapidly rotated in thedirection indicated by the arrows in Figs. 3 and 4, and when thecentrifugal force generated by such rotation is equal to or exceedsapredete1= mined amount, the arm 26 is rotated on its axis from theposition shown in Fig. 3 to the position shown in Fig. 4, thus providinga clear path for the firing pin 18 when released.

After the expiration of the time for which the timing train (not shown)is set, the release pin 24 is operated to free the firing pin 18,'andthe spring 20, expanding, forces the firing pin into engagement with theprimer 21 to explode the same and thus cause the detonation of thecharge of the shell.

With the arm 26 interposed between the firing pin 18 and primer 21,premature explosion of said primer by the accidental release, from anycause, of the firing pin 18 is impossible. To ensure absolute safety,the pin 27 is provided to positively hold the arm 26 in position untilthe fuse is subjected to the shock'of firing or an equivalent shock.

Referring now to Figs. 5 and 6, I provide, adjacent the outer end of thehole 14, a circular recess 30, having a centrally located hole in thebottom thereof which acts as a bearing for the circular projection 32 onthe bottom surface of a disc 33, this disc having a diameter slightlyless than the diameter of the recess 30. The upper surface of the disc33 is provided with diametrically arranged arcuate members 34, whichwhen the disc 33 is in the set, or normal position, as shown in thefigures, prevents any movement of the firing pin across the recess 30.Arranged on theupper surface of the disc 33, and approximately midwaybetween the members 34, as clearly shown in Fig. 6, is a primer holdingholding the primer 21. It is obvious therefore, that should the disc berotated in a clockwise direction, as viewed in Fig. 6, through an angleof approximately ninety degrees, the member or members 34 will be movedout of the path of movement of the firing pin and the primer 21 broughtinto said path of movement. In order to assure that the disc 33 can onlyrotate through an angle of approximately ninety degrees, I have cutaway'the periphcry of said disc as shown at 36, and have inserted a pin37 in the bottom face of the recess 30, which engages with one end of.the cut away portion 36 when the disc 33 is in set or normal position,and with the other end of said cut away portion when the disc is rotatedthrough an angle of approximately ninety degrees, the length of this cutaway portion 36 being proportioned to allow such movement. In order tohold the disc 33 and parts carried thereby in the set or normalposition, I provide the disc -with a hole in alinement with a similarhole in the fuse base 10, .and place in these holes a pin 38 whichfitstightly enough so that it will only be moved downwardly into thehole in the fuse base and out of the hole in the disc 33 by theshock offiring. One of the members 34 is made heavier than the other in order toensure the rotation of the disc 33 onits pivot when the fuse is rotated,and in order to ensure that the disc is retained in its rotated.position, I provide a spring pressed catch 48 in the fuse base, thatregisters with the depression 39 (shown in dotted lines in Fig.

6) in the undersurface of the disc 33. A closure 40 is provided for thehole in the base in alinement with the hole 14. The

disc 33 is provided with a hole 4=1 immediately in front of the primerholder 35, this hole being brought into alinement' with the hole 42 inthe fusebase that leads to the powder chamber 43.

The operation of the modification of my invention just described is asfollows, it

' by the difference in weight of the members 34. The rotation of thedisc 33 brings the primer 21 into the path of movement of the firingpin, which is released at thepropor instant by the timing gear (notshown) -toexplode the primer, the flames from the primer passing throughthe holes 41 and 42, which are at this instant in alinement, into thepowder charge in the chamber 43. As

the disc 33 rotates to its extreme limit, as determined by the pm 37 andcut away portion 36, the spring pressed catch 48 moves upwardly into thedepression 39, thus holding the disc 33 and associated parts in theoperated position.

Referring now to Fig. 7, which illustrates a modification similar to themodification illustrated in Figs. 5 and 6, 49 indicates the discrotatably mounted in the recess BOjtbis disc being similar inconstruction to the disc 33, above described, except that it does and isnot pronot carry a primer hold videdwitha hole 41; Instead, the primerholder is identical with the primer holder illustrated in Figs. 2 and 3,and is therefore,

designated by the refe'rence character 15. The disc 49 is cut away at50, which assists inoverbalancing the same and. thus assists in therotary movement and this-cut away portion is brought into alinement withthe hole 42 in the fuse base when the disc 49' is 'rotated to-theoperated position. The'op- I may vary the size, shape and arrangement ofparts constituting my improved device, Within wide limits withoutdeparting from the spirit of the invention. My invention is furtherdescribed and defined in the form -ofclaims as follows:

1. In a time fuse, the combination of a base,

.a firing pin in said base movable in a right line and at right anglesto the axis of the fuse in its flight, a primer lying in the path' ofmovement of saidfiring pin, and a safety device interposed between saidfiring pin and primer, a second safety device retaining said firstsafety device in its normal position. L

2. In a time.fuse, the combination of a base, a firing pin in said basemovable in a right line at right angles to the axis of the fuse in itsflight, a primer lying in the path of movement of said firing pin, and asafety device interposed between said firing pin and primer and movabletherefrom by centrifugal force, a second safety device retaining saidfirst safety device in its normal position, said second safet devicebeing operated by the shock of firing to release said first safetydevice.

3. In a time fuse, the'combination ofa. base, a firing pin in said basemovable in a right line and at ri ht angles to the axis of the fuse inits ight; means normally tendingto force said firing pin to its operatedposition, means for holding said firing pin in its normal position, aprimer lying in the path of movement of said firing pin, a safety deviceinterposed between said firing pin and primer, a second safety deviceretaining said first safety device in its normal' position, said safetydevices being operated by the shock of firing and centrifugal forcerespectively to clear the path of movement of the firing pm.

'4. In a time fuse,. the combination of'a base, a firing pin in saidbase movable at right angles to the axis of the fuse in its flight,means normally tending to force said firing pm to its operated position,means forholding said firing pin in its normal positon, a primer lyingin the path of movement of said firing pin, a-safety device interposedbetween said firing pin and primer,

a-sec'ond safety device retalning said first safety device in itsnormalposition, said second safety. device being operated by the shockof firing to release, said first safety device, said first safety devicebeing operat ed by centrifugal force tomove out of the path of movementof said firing pin, and releasing means for said firing pinoperatingafter the safety devices have operated.-

5. In a time fuse, the combination of a* base, a firing pin in. saidbase, said firing pm being located in a passage extending diametricallyof said base, a spring normally tending. to force said firing pin to itsoperated position, means for holding said firing pinin its normalposition, a primer lying in the path of movement of said firing pin, asafety device interposed between said firing pin and primer andmovabletherefrom by centrifugal force, and releasing means for said firing pinoperating after the safety devices have operated.

6. In a time fuse, the combination of a base, a firing pin in said base,said firing pin being located in a passage extending diametrically ofsaid base, a spring normally tending to force said firing pin to itsoperated position, means for holding said 15 firing pin in its normalposition, a primer lying in the path of movement of said firing pin, asafety device interposed between said firing pin and primer, a secondsafety de vice retaining said first safety device in its normalposition," said second safety device being operated by the shock offiring to release said first safety device, said first safety devicebeing operated by centrifugal force to move out of the path of movementof said firingpin, and releasing means for said firing pin operatingafter the safety devices have operated.

In testimony whereof, Ihave signed my name to this specification.

CHARLES H. PEARSON.

